Electrochemical Sensors Based On Fullerol Nanocomposites

In this paper,fullerol were prepared by simple and efficient TBAH catalytic alkali method.Nafion-C₆₀（OH）_n/GCE、S1/C₆₀（OH）_n/GCE and C₆₀（OH）_n-AuNCs@His/GCE were prepared by drop coating,self-assembly and electrochemical methods.Three novel electrochemical sensor for dopamine（DA）,Listeria monocytogenes DNA and nitrite（NO₂^-）were constructed based on fullerol nonocomposites.The main research contents are as follows:（1）The water-soluble fullerol(C₆₀（OH）_n)was synthesized by a reflux oxidation method under strong alkaline condition using fullerene and H₂O₂ as raw materials.Nafion-C₆₀（OH）_n/GCE was obtained by mixing Nafion solution with C₆₀（OH）_n solution and modifying it on the surface of the glassy carbon electrode.The results of electrochemical experiments show that the modified electrode has a significant electrocatalytic effect on the electrochemical reaction of dopamine in phosphate buffered saline（PBS）.Under the optimal conditions,the DPV oxidation peak current has a good linear relationship with dopamine concentration in the range of 0.2μmol/L²0μmol/L and 20μmol/L¹00μmol/L,and the detection limit is 0.011μmol/L（S/N=3）.In addition,the sensor has good reproducibility and stability,and is used for dopamine analysis in human serum with a recovery rate of 96.1%⁹7.3%.（2）Fullerol was deposited on the surface of glassy carbon electrode by electrochemical method,then immersed in probe DNA（S1）solution of Listeria monocytogenes,which was fixed on the electrode surface byπ-πstacking,and S1/C₆₀（OH）_n/GCE was obtained.The results of electrochemical experiments show that the electrochemical impedance of the modified electrode changes significantly after hybridization with the target DNA（S2）.Under the optimal conditions,the impedance variation has a good linear relationship with S2 concentration in the range of 1.0×10^-151.0×10^-9 mol/L,and the detection limit is 2.23×10^-16 mol/L（S/N=3）.In addition,the sensor has good stability and reproducibility,and is used for the analysis of target DNA in pure milk with a recovery rate of 101.0%¹04.0%.（3）C₆₀（OH）_n-AuNCs@His nanocomposites were synthesized by mixing in the dark,and then coated on the surface of GCE.After electrochemical scanning activation,C₆₀（OH）_n-AuNCs@His/GCE was obtained.The results of electrochemical experiments show that the modified electrode has a significant electrocatalytic effect on the electrochemical reaction of NO₂^-in PBS.Under the optimal conditions,the timing current has a good linear relationship with the concentration of NO₂^-in the range of1.0×10^-5 mmol/L¹0.0 mmol/L,and the detection limit is 3.78×10^-3μmol/L（S/N=3）.In addition,the sensor has the advantages of high sensitivity,wide linear range,low detection limit,good stability and selectivity,and is used for the analysis of soil leachate with a recovery rate of 98%¹07.9%.